(19)
(11) EP 0 349 135 A3

(12) EUROPEAN PATENT APPLICATION

(88) Date of publication A3:
11.04.1990 Bulletin 1990/15

(43) Date of publication A2:
03.01.1990 Bulletin 1990/01

(21) Application number: 89305763.8

(22) Date of filing: 07.06.1989
(51) International Patent Classification (IPC)5: G01N 25/72, G01M 13/04
(84) Designated Contracting States:
DE ES FR GB

(30) Priority: 27.06.1988 US 212360

(71) Applicants:
  • FORD MOTOR COMPANY LIMITED
    Brentwood, Essex CM13 3BW (GB)

    GB 
  • FORD FRANCE S. A.
    F-92506 Rueil-Malmaison Cédex (FR)

    FR 
  • FORD-WERKE AKTIENGESELLSCHAFT
    D-50725 Köln (DE)

    DE 
  • FORD MOTOR COMPANY
    Dearborn, MI 48120 (US)

    ES 

(72) Inventors:
  • Yerace, Daniel
    Belleville Michigan 48111 (US)
  • Zinkosky, Alexander Julius
    Dearborn Michigan (US)

(74) Representative: Messulam, Alec Moses et al
A. Messulam & Co. 24 Broadway
Leigh on Sea Essex SS9 1BN
Leigh on Sea Essex SS9 1BN (GB)


(56) References cited: : 
   
       


    (54) Method of locating friction generating defects in a multiple bearing assembly


    (57) A method of determining the location and type of dimensional defects, particularly friction generating defects, which comprises: (a) initiating simulated operation at ambient conditions of an assembly (10) having certain sliding or rolling contact surfaces; (b) sensing (25) any change in the temperature of such assembly surrounding each certain sliding or rolling contact surfaces (i) with a resolution of .02-1.0°C (preferably .1-.7°C) and (ii) during a time span of 2-10 seconds measured from such initiation to provide separated voltage signals for each location; (c) converting the signals to a digitised thermal map (32) ; and (d) comparing (34) the sensed digitised thermal map with a reference digitised thermal map for such an assembly without defects operated during the same time span and adjusted to compensate for any differing thermal conditions. Any deviations detected by such comparison representing defects.







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